What kind of players should I recruit for Fast break offense? I assume speed and ball handling as top traits (at least in real life)

A highly underrated attribute is FT since if you run FB/Press your tired opponents might send you to the foul line a lot. If your players can't shoot FTs you'll leave a lot of points on the floor.

ATH, SPD, BH are tops. LP is very helpful.

I'd rank it something like:
ATH

I’d put stamina a bit higher, personally, right below speed, since you can’t slow down. If you’re not playing zone, you need a lot of stamina to pull off FB well. It would be *a little* above speed if we were talking about a press defense, I only rate stamina under ath and def for the FB/press combo. But that’s beside the point since you play man.

And I also prefer per to LP even with FB, because the engine always likes it better so why fight it? But it is certainly nice to have a few “slash” guys who can draw a lot of fouls, for sure. Otherwise generally agree with the priority shopping list above.